US 9,803,972 B2Granted

Optical configuration for measurement device

AssigneeMitutoyo Corporation

InventorDavid William Sesko

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Abstract

A scanning probe is provided for use with a coordinate measuring machine. The scanning probe includes a rotary position detection configuration which outputs X and Y position signals indicative of a rotation of a stylus coupling portion about a rotation center, and an axial position detection configuration which outputs a Z position signal indicative of the position of the stylus coupling portion along the axial direction. The Z position signal is substantially insensitive to motion of the axial detection deflector in at least one direction that is transverse to the axial direction. The X, Y and Z position signals may be processed to determine a 3D position of a contact portion of the stylus, which may include utilizing the Z position signal in combination with known trigonometry of the scanning probe to remove axial motion cross coupling components from the X and Y position signals.

Claims24

Dependent claims

A scanning probe for a coordinate measuring machine, the scanning probe comprising:

a stylus suspension portion, comprising:
a stylus coupling portion that is configured to be rigidly coupled to a stylus;
and
a stylus motion mechanism that is configured to enable axial motion of the stylus coupling portion along an axial direction, and rotary motion of the stylus coupling portion about a rotation center;
and
a stylus position detection portion, comprising:
a light source configuration;
a rotary position detection configuration, comprising:
a rotary detection beam path configured to receive light from the light source configuration;
a rotary detection deflector that is located along the rotary detection beam path and that is coupled to the stylus suspension portion;
and
a rotary detector portion that receives a variable-deflection light beam from the rotary detection deflector and outputs X and Y position signals indicative of rotation of the stylus coupling portion about the rotation center;
and
an axial position detection configuration, comprising:
an axial detection beam path configured to receive light from the light source configuration;
an axial detection deflector that is located along the axial detection beam path and that is coupled to the stylus suspension portion to move in the axial direction in response to the axial motion, wherein the axial detection deflector also moves in at least one direction transverse to the axial direction in response to the rotary motion;
and
an axial detector portion that receives a variable-deflection light beam from the axial detection deflector and outputs a Z position signal indicative of a position of the stylus coupling portion along the axial direction, wherein the axial position detection configuration is configured such that the Z position signal is substantially insensitive to motion of the axial detection deflector in the at least one direction that is transverse to the axial direction.

15 more elements

A method for determining a 3D position of a contact portion of a stylus based on position signals received from a scanning probe that the stylus is attached to, the method comprising:

determining that the scanning probe has been positioned so that the contact portion of the attached stylus has come into contact with a workpiece that is being measured, wherein the scanning probe comprises:
a stylus suspension portion, comprising:
a stylus coupling portion that is configured to be rigidly coupled to a stylus;
and
a stylus motion mechanism that is configured to enable axial motion of the stylus coupling portion along an axial direction, and rotary motion of the stylus coupling portion about a rotation center;
and
a stylus position detection portion, comprising:
a light source configuration;
a rotary position detection configuration, comprising:
a rotary detection beam path configured to receive light from the light source configuration;
a rotary detection deflector that is located along the rotary detection beam path and that is coupled to the stylus suspension portion;
and
a rotary detector portion that receives a variable-deflection light beam from the rotary detection deflector and outputs X and Y position signals indicative of rotation of the stylus coupling portion about the rotation center;
and
an axial position detection configuration, comprising:
an axial detection beam path configured to receive light from the light source configuration;
an axial detection deflector that is located along the axial detection beam path and that is coupled to the stylus suspension portion to move in the axial direction in response to the axial motion, wherein the axial detection deflector also moves in at least one direction transverse to the axial direction in response to the rotary motion;
and
an axial detector portion that receives a variable-deflection light beam from the axial detection deflector and outputs a Z position signal indicative of the position of the stylus coupling portion along the axial direction, wherein the axial position detection configuration is configured such that the Z position signal is substantially insensitive to motion of the axial detection deflector in the at least one direction that is transverse to the axial direction;
receiving the X, Y and Z position signals from the stylus position detection portion;
and
processing the X, Y and Z position signals to determine a 3D position of the contact portion of the stylus.

19 more elements

A system for determining a 3D position of a contact portion of a stylus based on position signals received from a scanning probe that the stylus is coupled to, the system comprising:

a receiving portion for receiving X and Y position signals from a rotary position detection configuration of the scanning probe, wherein the rotary position detection configuration comprises:
a rotary detection beam path configured to receive light from a light source configuration;
a rotary detection deflector that is located along the rotary detection beam path and that is coupled to a stylus suspension portion, the stylus suspension portion including a stylus coupling portion that is rigidly coupled to a stylus and including a stylus motion mechanism that enables axial motion of the stylus coupling portion along an axial direction and rotary motion of the stylus coupling portion about a rotation center;
and
a rotary detector portion that receives a variable-deflection light beam from the rotary detection deflector and outputs the X and Y position signals that are indicative of the rotation of the stylus coupling portion about the rotation center;
a receiving portion for receiving a Z position signal from an axial position detection configuration of the scanning probe, wherein the axial position detection configuration comprises:
an axial detection beam path configured to receive light from the light source configuration;
an axial detection deflector that is located along the axial detection beam path and that is coupled to the stylus suspension portion to move in the axial direction in response to the axial motion, wherein the axial detection deflector also moves in at least one direction transverse to the axial direction in response to the rotary motion;
and
an axial detector portion that receives a variable-deflection light beam from the axial detection deflector and outputs the Z position signal that is indicative of the position of the stylus coupling portion along the axial direction, wherein the axial position detection configuration is configured such that the Z position signal is substantially insensitive to motion of the axial detection deflector in the at least one direction that is transverse to the axial direction;
and
a processing portion for processing the X, Y and Z position signals to determine a 3D position of the contact portion of the stylus.

9 more elements

Dependencies are inferred from the claim text.